An inbred line of Syrian hamsters with frequent spontaneous adrenal tumors.

SUMMARY Two new inbred lines of Syrian hamsters are described in their 13th , to 20th and 24th to 34th generations of brother-sister mating. One of the two lines, identified as BlO 4.24, shows a high incidence of adrenal tumors (in about 50% of the animals). The other, BlO 45.5, shows a significantly lower incidence (in about 17% of the animals). Histologically, these were the types of adrenal tumors previously described in this species. In 12 other inbred strains the adrenal tumor incidence averaged 23%. The BlO 4.24 line (high incidence of adrenal tumors) also showed a higher incidence of histological anomalies of sex glands and pituitary which, however, was not related to the adrenal neoplasms. There was also present a high incidence of obesity in females which was not correlated with the observed anomalies of the endocrine system. Genetic factors seem to explain the previously reported highly variable incidence of spontaneous adrenal tumors of hamsters.